Improved Unarmored Specialist (Combat)

Benefit: As long as you do not have any armor bonus to AC (such as from wearing armor, or from the spell mage armor), double your Dexterity bonus for the purposes of your AC (for example, a character with a Dexterity score of 15 would have a +4 Dexterity bonus to AC, because the normal bonus is +2, and doubled it becomes +4). Anything that would cause you to be denied your Dexterity bonus to AC still causes you to lose the entire bonus.